(a) Field of the Invention
Embodiments of the present invention relate generally to flat panel display fabrication. More specifically, embodiments of the present invention relate to a mask for exposure during a flat panel display fabrication process, and a method of fabricating a substrate using the mask.
(b) Description of the Related Art
Today, flat panel display devices are fabricated in various ways. The flat panel display devices can include various display devices such as a liquid crystal display, an organic light emitting device, an electrophoretic display, an MEMS display device, and a 3D display device.
In each of these devices, there exists a growing demand for forming fine patterns. Unlike the general semiconductor field, the flat panel display field has not seen much demand for fine patterns, or improved fine pattern formation techniques.
However, in the drive for increased resolution of these display devices, pixel sizes have shrunk to below the critical resolution of current exposers, thus spawning a demand for fine pattern formation.
Currently, in order to form a fine pattern beyond the critical resolution of the exposer, an exposer having a high resolution is used. That is, the critical resolution is reduced by changing a light source used in the exposer, or by increasing an NA value of the exposer. Previously, the exposer used for manufacturing the display device used a complex wavelength light source having a plurality of light sources, but this limited resolution. The critical resolution was reduced by using a single light source, of a single wavelength. However, the method requires remodeling of the exposer and introduction of new equipment, which entails significant time and cost. Further, since the change to a single wavelength light source and the increase in the NA value reduce the critical resolution and a depth of focus, non-uniformity defects can occur in a display device field using a large-area substrate.
Another approach has been to form the fine pattern by using a mask. In this case, since the fine pattern is formed beyond the critical resolution of the exposer, many defects occur in the formed fine pattern, such that yield reduction and defect frequency become issues.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.